Irving Kristol, father to Fox News talking head Bill Kristol, was the intellectual architect of neoconservatism, a fierce anti-communist, and staunch Republican. So why did FBI counterintelligence agents investigate his contacts with a suspected Soviet agent in the 1980s?

The elder Kristol made no secret of his youthful flirtations with socialism. Like many neoconservatives, he was a college Trotskyite who lurched radically rightward after World War II. By 1982, he was universally acknowledged as a chief engine of right-wing thought in American politics and one of the minds behind the Reagan Revolution. Which is why it's so curious that, according to FBI documents obtained by Gawker under the Freedom of Information Act, he was the subject of a five-month FBI counterintelligence investigation in 1988.

The FBI heavily redacted the documents—citing national security in many instances—so it's difficult to make out exactly what happened. But it seems fairly clear that, sometime around May of 1988, the FBI's counterintelligence division came to possess a notebook or address book belonging to a suspected Soviet agent. And Irving Kristol's name was in it. That launched a five-month investigation into Kristol's background, including criminal record checks, interviews with "assets" at the school where he taught, and eventually an interview with Kristol himself, conducted under a "pretext" so as to avoid letting him know the true nature of the investigation. This despite the fact that Kristol had already been subjected to an FBI background check in 1972, when he was considered for a job in the Nixon White House, and came up clean.

Here's the memo from a New York agent seeking permission to open the investigation to "determine the relationship, if any, between [Kristol] and [redacted]"—its file number begins with 105, which in the FBI's case file system designates a foreign counterintelligence investigation. (You can read all the investigative documents from the file at the bottom of this page.)

And this heavily redacted memo makes clear that the FBI found something bearing an "inscription" with Kristol's name:

The records make clear that the FBI believed a Soviet agent had targeted or been in contact with Kristol. Here's a portion of memo ordering agents to canvass their New York University "assets," or informants, for information about Kristol's contacts with "Soviet nationals" (Kristol taught there; none of the assets had any information about him to offer.)

The investigation also included criminal record checks, including a request to the New York City Police Department to furnish any records it had on Kristol:

Because of Kristol's stature, the field agents investigating him asked for permission to approach him for an interview from headquarters. That permission was granted, on the condition that the agents come up with a "pretext" for the interview that wouldn't give up the "sensitive source" of the information connecting him to a suspected spy:

When the agents did interview Kristol, he denied meeting the person that the agents were interested in, and laid out all of his innocuous contacts with Soviets, including an interview he gave to a reporter for the Russian news service TASS.

Kristol's denials were apparently enough to convince the agents that one of the nation's chief critics of Soviet communism was not, in fact, secretly spying on behalf of Soviet communists. The investigation was dropped not long after the interview. One of the memos refers to Kristol (or perhaps another target of the suspected spy; the name is redacted) as being in a "position [that] would certainly be of interest to Line PR," which seems to be a term for the KGB's political intelligence division. The writer speculated that the Soviets may have simply been interested in talking to Kristol for mundane diplomatic reasons—to get a lay of the land—as opposed to actual nefarious spying.